The proliferation of houseboats has played a part in raising pollution levels, especially faecal pollution, in Vembanad Lake, a designated Ramsar site.
Recently, a study carried under the aegis of the Alappuzha unit of the Kerala State Pollution Control Board (KSPCB) has revealed the presence of high levels of coliform bacteria in Vembanad Lake, especially at Punnamada, a houseboat boarding point. The total coliform count in water collected from Punnamada was 8,000 Most Probable Number (MPN)/100 ml in April 2019, against the permissible limit of 500 MPN/100 ml. It stood at 4,000/100 ml and 2,000/100 ml in May and June, 2019. Officials said illegal houseboats were discharging waste water directly into the waterbody, with the Vembanad lake ecosystem taking the brunt.
Adding to the woes is a dysfunctional sewage treatment plant (STP) at H-Block. The plant operated by the District Tourism Council was closed several months ago after the KSPCB found flaws in its functioning, forcing the boats to discharge waste water directly into the lake.